1. Description of Related Art
The present invention relates to a powered actuating device for a closure panel of a vehicle, such as a hood or a rear lift gate for a trunk.
2. Background of the Invention
As is known, vehicles normally have a rear access opening to a luggage compartment, and a door assembly for closing the access opening.
More specifically, door assemblies are known, as described for example in U.S. Pat. No. 6,516,567, comprising a lift gate hinged to a fixed horizontal axis of the vehicle; one or more actuating devices interposed between the lift gate and a rear portion of the vehicle body distinct from said axis and delimiting the luggage compartment; and a motor for selectively controlling the actuating devices.
Known door assemblies can normally be set to a first and second operating configuration, in which the rear access opening of the vehicle is fully open and closed respectively.
More specifically, when the door assembly is in the fully-open configuration, the lift gate is detached from the rear portion of the vehicle body and fully raised with respect to its hinge axis so that the access opening is completely clear; and, in the closed configuration, the lift gate is lowered with respect to its hinge axis, and rests against the rear portion of the vehicle body defining the access opening to the luggage compartment, so that the access opening is fully closed.
Known door assembly actuating devices each comprise a telescopic arm and a gas spring, which are interposed between, and connected to separate parts of, the lift gate and the rear portion of the vehicle body, so as to extend side by side.
More specifically, the telescopic arm comprises a first and second member fixed to the rear portion of the vehicle body and to the lift gate respectively, and provides for moving the door assembly from one operating configuration to the other.
The first member of the telescopic arm is fitted with a screw connected functionally to the motor, and the second member is fitted with a nut screw integral with the lift gate and connected to the screw to permit slide of the second member with respect to the first member and extension/contraction of the telescopic arm.
The door assembly is moved from the closed to the open configuration by operating the motor in a first rotation direction.
The motor rotates the screw on the first member, so that the nut screw translates with respect to the screw in such a direction as to move the second member away from the first member and so extend the telescopic arm.
The lift gate, hinged to the fixed axis of the vehicle and connected to the second member of the telescopic arm, is therefore raised with respect to its hinge axis to move the door assembly into the fully-open configuration.
The door assembly is moved from the fully-open to the closed configuration in the same way, by operating the motor in a second rotation direction to contract the telescopic arm.
Contraction of the telescopic arm lowers the lift gate with respect to its hinge axis, so as to move the door assembly into the closed configuration.
The gas spring provides for maintaining equilibrium of the lift gate, when the motor is deactivated and the door assembly is in the fully-open configuration, by counteracting the weight of the lift gate.
Operation of the telescopic arm, in fact, requires that the screw and nut screw be connected reversibly, which means provision must be made to prevent the lift gate being lowered with respect to its hinge axis under its own weight when the motor is deactivated.
Known actuating devices require separate attachment points for the gas spring and the telescopic arm.
As a result, known devices are bulky, and limit access to the luggage compartment when loading large-size objects.
It is an object of the present invention to provide a powered actuating device for a closure panel of a vehicle, designed to eliminate the aforementioned drawback typically associated with known devices.